Manhunter Ends With Issue #38

According to writer Marc Andreyko, who posted the information on his Facebook page, Manhunter has once again been cancelled at DC. Andreyko wrote:

Marc Andreyko sadly announces Manhunter's cancellation. again - anyone up for a THIRD letter-writing campaign ('specially retailers)?
The cancellation will be the book’s second. The first came with issue
#25, and was due to sales. Despite being critically acclaimed, the
series, which told the story of Kate Spencer a newest iteration of the
hero in the DC Universe, did not see sales sufficient enough to
maintain it as an ongoing. There was considerable fan outcry at the
cancellation, which was noticed by DC Executive Editor Dan DiDio, At
WizardWorld: Philadelphia in 2006, DiDio announced that the series
would return for a limited engagement, with the promise that, if there was fan support, the series would return as an ongoing.

A year passed between issues #26-#30, and then, in June the series returned as an ongoing with issue #31. Sales estimates of issue #33 (which shipped in August) suggest that the issue sold roughly 12,000 copies, down from an estimated 15,000 copies for issue #31.
When contacted by Newsarama, DC Comics confirmed that Manhunter will end with issue #38 in January.